Rib orientation and implications for orthograde positional behavior in nonhuman anthropoids

Miyuki Kagaya, Naomichi Ogihara, Masato Nakatsukasa

Research output: Contribution to journalArticlepeer-review

5 Citations (Scopus)

Abstract

Strong caudal obliquity of the lower ribs is one of the assumed characteristics of the thoracic region in hominoids and Ateles. Strong caudal obliquity keeps the scapula of the weight-bearing forelimb on the dorsal surface of the trunk via the serratus anterior muscles during propulsion (Stern et al. 1980). We examined the orientation of odd-numbered ribs in lateral view in remounted thoracic skeletons of fifteen nonhuman anthropoids. Hominoids exhibit pronounced caudal obliquity in the seventh and ninth ribs compared to Old and New World monkeys. The position of the maximum thoracic cage width, which approximates the attachment of the serratus anterior muscle, is more caudally located in Hylobates and Pongo. The overall pattern of rib obliquity is generally similar between New and Old World monkeys, including Ateles. Perhaps not only forelimb suspensory behavior but also various orthograde positional behaviors are related to the strong obliquity of the lower ribs; however, further investigation is necessary.

Original languageEnglish
Pages (from-to)305-310
Number of pages6
JournalPrimates
Volume50
Issue number4
DOIs
Publication statusPublished - 2009
Externally publishedYes

Keywords

  • Forelimb suspensory behavior
  • Functional adaptation
  • Hominoids
  • Rib obliquity

ASJC Scopus subject areas

  • Animal Science and Zoology

Fingerprint

Dive into the research topics of 'Rib orientation and implications for orthograde positional behavior in nonhuman anthropoids'. Together they form a unique fingerprint.

Cite this